No matter how often the Iranians say "no," there are people who'll keep insisting that the United States has not asked. The BBC reports:

On Saturday, US Vice-President Joe Biden suggested direct talks, separate to the wider international discussions due to take place later this month. … He said Washington was prepared to hold one-to-one talks with Iran "when the Iranian leadership, supreme leader, is serious".

"That offer stands, but it must be real and tangible and there has to be an agenda that they are prepared to speak to. We are not just prepared to do it for the exercise," he said.

On Sunday, Iranian Foreign Minister Ali Akhbar Salehi welcomed the offer, saying Iran had no "red lines".

Whoops. The foreign minister spoke too soon. In a speech posted online by Ayatollah Ali Khameini:

Iran's supreme leader, however, said negotiations with the US "would solve nothing".

"You are pointing a gun at Iran saying you want to talk. The Iranian nation will not be frightened by the threats," he said.